diff --git a/Rakefile b/Rakefile
index 831187d5f5875ccac120ecc109aa0a9676b4ff6a..03b8a952c3a938f7435c532d51f00d5fcb81923a 100755
--- a/Rakefile
+++ b/Rakefile
@@ -94,7 +94,7 @@ RDoc::Task.new do |rdoc|
 
   rdoc.options << '-f' << 'sdoc'
   rdoc.options << '-T' << 'rails'
-  rdoc.options << '-c' << 'utf-8'
+  rdoc.options << '-e' << 'UTF-8'
   rdoc.options << '-g' # SDoc flag, link methods to GitHub
   rdoc.options << '-m' << RDOC_MAIN